| Patent application number | Description | Published |
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| 20100286928 | METHOD AND DEVICE FOR DETERMINING IMAGES FROM X-RAY PROJECTIONS - A method and a device for determining attenuation coefficients for an object using a movable X-ray source and a detector, which is provided for recording projections, is provided. The method includes specifying a trajectory for the movable X-ray source, specifying positions on the trajectory for determining a derivative of projections recorded by the detector, specifying a plurality of scanning positions for each of the specified positions, following the trajectory with the X-ray source and recording a projection for each scanning position, numerically calculating a projection derivative in relation to the trajectory path for each of the positions using the projections recorded for the associated plurality of scanning positions, and determining attenuation coefficients for the object from the calculated projection derivatives using a theoretically exact or approximate rule for the reconstruction. | 11-11-2010 |
| 20100329534 | METHOD AND DEVICE FOR THE ACQUISITION OF X-RAY IMAGES FOR A THREE-DIMENSIONAL IMAGE RECONSTRUCTION - A method and an X-ray image acquisition system for the acquisition of X-ray images of a region of interest of an examination object from a multiplicity of angles of view for an 3-D image reconstruction are provided. The X-ray image acquisition system comprises an X-ray focus and an X-ray detector, which can be separately positioned and oriented relative to each other. The X-ray focus is moved along a combination of straight line segments and/or arc segments for the acquisition of X-ray images. The X-ray detector is oriented relative to the X-ray focus and moved in such a way that the region of interest is projected completely onto the X-ray detector upon each image acquisition. | 12-30-2010 |
| 20110069807 | METHOD AND APPARATUS FOR DETERMINING AN IMAGE FROM X-RAY PROJECTIONS RECORDED WHEN TRAVERSING A TRAJECTORY - A method for determining attenuation coefficients for an object using a movable x-ray source and a detector for recording projections is provided. The method includes defining a trajectory for the movable x-ray source, defining filtering lines for the filtering of projection data, and defining positions on the filtering lines, at which the projection derivative is to be formed using a mathematical algorithm for a back-projection. The method also includes defining sampling positions on the trajectory, traversing, by the x-ray source, the trajectory and recording a projection for each sampling position. Projection derivatives with respect to the trajectory path are calculated numerically for each of the positions directly on the filtering lines, and using a mathematical algorithm, attenuation coefficients are determined for the object from the calculated projection derivatives, for the reconstruction. | 03-24-2011 |
| 20110075794 | Method and Device for Generating a Three-Dimensional X-Ray Imaging - A method is provided for quickly and simply generating a three-dimensional tomographic x-ray imaging. Tomosynthetic projection images are recorded from different recording angles along a tomosynthetic scanning path and three-dimensional image data is reconstructed from the tomosynthetic projection images. The tomosynthetic projection images are recorded by a tomosynthetic x-ray device with a plurality of x-ray sources arranged on a holder at a distance from one another. Each projection image is recorded by a different x-ray source being fixed in one place during recording the tomosynthetic projection images. | 03-31-2011 |
| 20110075809 | METHOD AND DEVICE FOR RECORDING A PROJECTION DATASET OF AN OBJECT USING A PLURALITY OF X-RAY SOURCES - A method for recording a projection dataset of a object to be recorded using a plurality of X-ray sources is provided, which X-ray sources are spaced apart from one another on average by an angle α relative to an isocenter. A plurality of projection images from different recording directions are recorded in succession while activating the corresponding X-ray sources. Two X-ray sources are activated in succession having a spacing of at least 2 α relative to the isocenter. | 03-31-2011 |
| 20110085636 | X-Ray System and Method for the Generation of a Scan Path - A method for generation of a scan path for an x-ray source and/or an x-ray detector of an x-ray system is provided. CT-type imaging on the x-ray system is enabled by traversing the scan path upon simultaneous acquisition of a series of x-ray images. An original scan path of the x-ray source and/or of the x-ray detector is provided, where the scan path is defined by a series of original acquisition points. A viewing axis from the x-ray source to the object and/or the detector is identified for at least one acquisition point on the scan path. A modified scan path is generated by displacement of the at least one acquisition point at least partially along the viewing axis so that the scanning movement upon traversing the modified scan path can be reproduced as in the original scan path. | 04-14-2011 |
| 20110085637 | Reconstruction of 3D image datasets from x-ray and cone-beam data - A method for producing a 3D image dataset of an object with an imaging system having an x-ray source and an x-ray detector is provided. A series of two-dimensional arrays of cone beam data from the detector is acquired while the source moves along a substantially planar trajectory around the object. The trajectory is described by a series of source points serially numbered by a counter parameter. The cone beam data is differentiated with respect to the counter parameter at a fixed ray direction to produce a derivative of the cone beam data. The derivative is filtered with a Hilbert-like filter to produce filtered cone beam data. The acquired or the filtered cone beam data is multiplied with a redundancy weighting function. The cone beam data is back-projected to reconstruct a 3D image dataset. | 04-14-2011 |
| 20110091085 | Modification and elimination of back projection weight during the CT image reconstruction - At least one embodiment of the invention relates to a method for the reconstruction of image data from an examined object, using measuring data, wherein the measuring data were first recorded during a relative movement between a radiation source on a computer tomography system and the examined object. In at least one embodiment, the image reconstruction is based on a back projection of the filtered measuring data. During the back projection, a back projection weight that depends on the respective image point is used and the power with which the back projection weight is used is selectable. | 04-21-2011 |
| 20110268341 | Method for Reconstruction of a Current Three-Dimensional Image Dataset of an Object During a Monitoring Process and X-Ray Device - A method for reconstruction of an actual three-dimensional image dataset of an object during a monitoring process is proposed. Two-dimensional. X-ray projection images which correspond to a recording geometry are continuously recorded from different projection angles. The three-dimensional image dataset are reconstructed from a first number of these projection images, especially by a back projection method. The proportion of the oldest projection image contained in the current three-dimensional image dataset is removed from the three-dimensional image dataset and the proportion of the actual projection image is inserted in the three-dimensional image dataset after each recording of the actual projection image. | 11-03-2011 |
| 20110274335 | Method for recording and reconstructing a three-dimensional image dataset and x-ray apparatus - A method for recording and reconstructing a three-dimensional image dataset is proposed. A plurality of projection images are acquired under different recording geometries in relation to an object to be recorded by an X-ray apparatus, in particular a C-arm X-ray apparatus. At least two projection images are recorded for at least one recording geometry, in particular for every recording geometry. The three-dimensional image dataset is reconstructed from the project images. | 11-10-2011 |
| 20110286629 | Method for reconstruction of a two-dimensional sectional image corresponding to a sectional plane through a recorded object and x-ray device - A method for reconstruction of a two-dimensional sectional image corresponding to a sectional plane through a recorded object from two-dimensional projection images recorded along a recording trajectory at different projection angles with an X-ray device is proposed. The sectional plane having at least two intersection points with the imaging trajectory is selected. After selection of the sectional plane, an intermediate function on the sectional plane is determined by backprojection of the projection images processed with a differentiation filter. The object densities forming the sectional image are determined from the intermediate function by a two-dimensional iterative deconvolution method. | 11-24-2011 |
| 20120008740 | METHOD FOR RECONSTRUCTION OF A THREE-DIMENSIONAL IMAGE DATA SET AND X-RAY DEVICE - A method for reconstruction of a three-dimensional image data set from projection images of an object captured with an X-ray device from different projection angles is proposed. At least one sub-area of the object is outside the coverage of the X-ray device, or as a result of strong attenuation by a metal so that no projection data is present in the sub-area. Filter lines are determined n the projection images. A first local transformation is performed along the filter lines on the projection images. The missing projection data on the transformed projection data is augmented. A non-local transformation is performed on the transformed projection data for determining of filtered, augmented projection data. The non-local transformation is different from a ramp filter which is created by the first local transformation and the non-local transformation. The three-dimensional image data set is determined by back-projection of the filtered, augmented projection data. | 01-12-2012 |
| 20120140875 | METHOD FOR OBTAINING A 3D RECONSTRUCTION OF AN OBJECT, AND X-RAY DEVICE - 3D reconstructions can be calculated from grayscale X-ray images taken at different angular positions of an X-ray source and detector rotatable about a common axis. In the present case, X-ray radiation is applied to the object to be imaged such that one half of the X-ray detector receives radiation which differs in one characteristic from the radiation received by the second half of the detector via the object. A kind of dual-energy imaging can then be carried out in a single pass through the angular positions, enabling two 3D reconstructions to be generated simultaneously and then merged. | 06-07-2012 |
| 20120201352 | METHOD FOR OBTAINING A 3D IMAGE DATASET OF AN OBJECT OF INTEREST - A method for obtaining a 3D image dataset of an object of interest is proposed. A plurality of 2D X-ray images are captured and a 3D reconstruction is carried out using filtered back projection. The projection parameters have been measured with the aid of a calibrating phantom, possibly using an interpolation or extrapolation of such measurements. A model of effect strings of the components in an X-ray imaging device is obtained, and the model parameters are identified based on imaging of a calibrating phantom. A projection matrix can then be calculated for any positions on any desired trajectories, without having to use imaging of a calibrating phantom at precisely that position and desired trajectory. | 08-09-2012 |
| 20120301008 | Method for acquiring a 3D image dataset associated with an image object - A method for acquiring a 3D image dataset is proposed. A 3D X-ray image dataset of an image object is acquired during scanning of a partial circle by X-ray radiation source and X-ray radiation detector. A first and a second 3D image datasets are calculated from the acquired image dataset. Redundancies are eliminated by averaging the first and second 3D image datasets. A filtering that is antisymmetric in respect of a center of symmetry is performed in respect of the 2D image datasets in calculating the second 3D image dataset. Said filtering has a row-by-row Hilbert transform. Suitable weights can be specified based on an axis defined in space. | 11-29-2012 |
| 20130003916 | SYSTEM AND METHOD FOR TOMOGRAPHIC RECONSTRUCTION IN THE 2D PARALLEL-BEAM GEOMETRY - An alternative analytical method for tomographic reconstruction in the 2D parallel-beam geometry is presented. This method may follow a filtering and backprojection scheme and may involve a global filtering in the projection domain and a local filtering in the image domain. For example, the method may include applying Hilbert filtering to the received projection data, computing an antiderivative of the filtered data, backprojecting the antiderivative into the image domain, and computing the 2D Laplacian of the backprojection image. | 01-03-2013 |
| 20130004045 | SYSTEM AND METHOD FOR 3D TOMOGRAPHIC IMAGE RECONSTRUCTION IN THE CIRCULAR GEOMETRY - A technique for 3D tomographic image reconstruction in the circular geometry (e.g., cone-based circular geometry) is disclosed. The technique may include data filtering using an initial 2D Laplace operation and a subsequent, non-local 2D filtering operation. The first filtering step thus only acts locally on the data so that it can be carried out accurately even in presence of (transaxial) data truncation. This feature may provide increased flexibility with respect to truncated projections as compared with certain standard FBP methods. Simulation studies show that the technique yields, for heavily transaxially-truncated data, an image quality that is similar to that obtained with the Feldkamp method applied with an explicit extrapolation scheme. | 01-03-2013 |
| 20130028498 | BACK-PROJECTION OF A PROJECTION IMAGE DATA SET WITH DEPTH-DEPENDENT FILTERING - For filtered back-projection of a projection image data set, the projection image data set is cosine-weighted. The cosine-weighted projection image data set within the image plane of the projection image data set is subjected to a two-dimensional Radon transformation. The Radon transform of the cosine-weighted projection image data set differentiated with respect to the distance from an image origin of an image coordinate system. The derivative of the Radon transform is redundancy-weighted. The redundancy-weighted derivative is subjected to a two-dimensional Radon back-transformation. The Radon back-transform is differentiated and back-projected with respect to an image column coordinate. A differentiation step width entering into the differentiation is varied depending on depth. | 01-31-2013 |
| 20130034201 | APPARATUS FOR X-RAY IMAGING FOR PROJECTION RADIOGRAPHY AND COMPUTED TOMOGRAPHY, AND METHOD FOR X-RAY IMAGING - An X-ray imaging apparatus has at least one X-ray image system rotatable about an examination volume. The X-ray image system is controlled such that during a continuous rotation of the system, at least one 2D projection image is recorded. An image generation facility generates the 2D projection image from the measured data. The X-ray source includes an X-ray focus which can be changed in terms of position, which, during the recording of the 2D projection image, moves counter to the direction of rotation of the X-ray image system such that its spatial position in a fixed coordinate system does not change. The X-ray detector records several 2D partial images, from which the 2D projection image is calculated with the rotational movement of the X-ray detector being at least approximately compensated. The 2D projection images have significantly reduced image blur. | 02-07-2013 |
| 20130136333 | METHOD FOR RECONSTRUCTING A RECONSTRUCTION DATA SET CONTAINING TWO-DIMENSIONAL VIRTUAL X-RAY IMAGES - A method reconstructs a reconstruction data set containing virtual X-ray images of projection images of a target region recorded with an X-ray device. The projection images being recorded at different positions of an X-ray source along a scanning trajectory. The method includes defining an imaginary position of the X-ray source for each virtual X-ray image. For each virtual X-ray image and each pixel to be reconstructed in the X-ray image a virtual beam section, covering the target region, of the path between the imaginary position of the X-ray source and the pixel is defined. For each projection image, an integral is determined from the relationships between the forward projection and the filtered back-projection by re-parameterizing. A projection value of the virtual X-ray image from the integrals determined is combined. | 05-30-2013 |
| 20130243293 | METHOD FOR REDUCING MOTION ARTIFACTS - Artifacts result from unrecorded, stochastically distributed relative movements of a radiation source, radiation detector, and/or the object during a scanning process. The artifacts occur when a three-dimensional image dataset is reconstructed from two-dimensional projection images acquired from different projection directions. Geometric parameters describing an acquisition geometry for each projection image are taken into account during the reconstruction. The correction includes filtering the projection images to obtain a set of filtered first intermediate images. A set of second intermediate images are formed by filtering the projection images with a second filter. A three-dimensional reconstruction dataset is constructed from the filtered projection images filtered by way of the second filter, and forward projection is applied in the projection directions. Displacement information is determined for each projection direction by comparing the respective first intermediate image with the second intermediate image, and the geometric parameters are adjusted as a function of the displacement information. | 09-19-2013 |
| 20140050295 | METHOD AND X-RAY DEVICE TO DETERMINE A THREE-DIMENSIONAL TARGET IMAGE DATA SET - In a method and x-ray device to determine a three-dimensional target image data set showing at least one partial region of interest of an acquisition region, wherein the image data of the three-dimensional target image data set are reconstructed from two-dimensional projection images acquired from various projection directions, first projection images are acquired without a collimation of the radiation source from first projection directions and a three-dimensional overview image data set of the acquisition region is reconstructed from the first projection images. The partial region of interest is selected in the overview image data set. Second projection images are acquired, with collimation at the partial region, from second projection directions, the second projection directions differing from the first projection directions. The target image data set showing the acquisition region and the partial region of interest is reconstructed from all first and second projection images. | 02-20-2014 |
| 20140050302 | METHOD FOR THE DETERMINATION OF DUAL ENERGY IMAGE DATA RECORDS AND X-RAY FACILITY - A method for determining at least one three-dimensional image data record to be displayed of a target area from two sets of projection images recorded with x-ray spectra using different energy maxima. The method includes recording the first projection image via a first X-ray spectrum and different first projection directions and of the second projection image via the second X-ray spectrum and different second projection directions. The second projection directions differ at least partially from the first projection directions. A three-dimensional anatomy image data record is reconstructed from the first and the second projection images. A three-dimensional spectral image data record is reconstructed by a weighted combination of a first three-dimensional reconstruction image data record, reconstructed from the first projection images, and a second three-dimensional reconstruction image data record is reconstructed from the second projection images. The anatomy image data record and the spectral image data record are displayed. | 02-20-2014 |
| 20140093032 | CONFIGURATION AND METHOD FOR TOMOSYNTHETIC FLUOROSCOPY - A configuration and an associated operating method for tomosynthetic fluoroscopy utilize an x-ray emitter and with an x-ray detector. The configuration further contains a mounting device, which is rotatably mounted about a rotational axis and about which the x-ray emitter is arranged such that the optical axis of the x-ray emitter is directed to the x-ray detector and that, in the case of a rotation of the mounting device, the focus of the x-ray emitter describes a circular path. An advantage offered by the invention lies in ensuring robust tomosynthetic fluoroscopy. | 04-03-2014 |
